Just wanted to finish up and document what transpired. Possibly help other people that may have a similar issue with their gas level sender unit.
So one fine rainy day, I was in the garage and decided to remove the gas sender unit in hopes of finding out why I'm getting incorrect gas level readings. I removed 3 bolts holding down the metal cover for the connector. Removed connector , then removed remaining 2 bolts. I gripped the sender unit and pulled straight up allowing the gas to drain from the unit back into the tank.
I removed the clip from the bottom of the sender unit and removed the casing exposing the inerts. I forgot to take a pic. Its just a float that moves along 4 wire lines. This was the first time I've seen a sender unit inerts but I could not find any sticking of the float as I moved it up and down the wires. Possibly there may be a bad electrical connection or the problem could be in the wiring to the gauge or the gauge itself. It was getting late so I put the unit back together and reinstalled it into the gas tank.
I decided to bite the bullet and order a new unit from our host. Here's pics of the unit as packaged
So I'm holding the unit and notice the yellow label. It says to remove a pin before installation. I'm Looking all over for a pin that I don't know where it is nor how big. I noticed that there was a bubble under the yellow label, so I pulled it back and there it was. Here are pics.
I removed the pin and the label.
I removed the current gas level sender unit as before, then proceeded to remove the black rubber gasket. I glanced at the new gasket to be installed and it was made of cork. I wasn't too thrilled on using a cork gasket. After reviewing the black rubber material for damage, I elected to reuse the black rubber one. So I did not touch it and went ahead and installed the new sender unit.
Here's a pic of the cork gasket.
Tightened all bolts, re-attached battery and went on an errand. Fuel sender appeared to do its job at 200 miles the gauge should read just above half full.
I just realized that the original problem is that it stayed at just about half full. Which means that the problem could still exist. (I've been driving the car and this second fillup coincedently is at approximately the same mileage on the trip meter when the original problem started. The only way to make sure is to drive the car about 50 miles to make sure it drops below the half full mark, then I will know that the sender is working correctly. I'll post or edit this post to follow up on the this issue.